Preparation of metal sulfonate compositions



Patented Apr. 13, 1954 PREPARATION- OF METAL SULFONATE COMPOSITIONSThomas J. Wishlinski, Lansing, Ill., and Fredcrick W. Schuessler,Valparaiso, Ind., assignors to Standard. Oil. Company, Chicago, 111., acorporation of Indiana No Drawing.

Application May 25, 1951,

Serial No. 228,374

18 Claims. 1

This invention relates to: an improved process for manufacturingpetroleum sulfonate compo,- sitions and bituminous compositionscontaining same. More particularly; it relates to the manufacture ofstabilized water-insoluble metal sulfonate containing adjuncts forbituminous coating materials such as paving asphalts.

Bituminous materials, such as normally liquid road oils and normallyliquid to normall solid asphalts, are frequently compounded with variousadjuncts to improve; the adhesiveness of the bitumen to wetmineralaggregates.v Among the various adjuncts, employed for this purpose aresoaps of sulfonic acids, particularly the alkaline earth metal and heavymetal soaps of sulfonic acids obtained in the treatment of hydrocarbonoils With concentrated or fuming sulfuric acid. One source of suchsulfonic' acids is the sludge obtained. in the: treatment of hydrocarbonoils with sulfuric acid of about. 95 percent strength or above, andpreferably fuming sulfuric acid. It is an object of the presentinvention to provide a method of preparing stable, homogeneous adjunctsfor incorporation in paving asphalts and the like containingwater-insoluble sludge acid soaps.

A further object of the invention is to provide a method of preparing astable homogeneous metal sulfonate containing adjunct for bituminousmaterials comprising an aromatic hydrocarbon and water-insoluble metalsulfonates derived from an acid sludge resulting from the treatment of ahydrocarbon oil with concentrated or fuming sulfuric acid.

Still another object of the invention is to provide a method ofpreparing a stable homogeneous adjunct comprising a substantialproportion of a Water-insoluble metal sulfonate obtained from an acidsludge, resulting from the treatment of a hydrocarbon oil withconcentrated or fuming sulfuric acid, an aromatic hydrocarbon, Water,al- 001101 and mineral oil which may be added to a bitumen to promotecoating of Wet aggregates. A still further object i to provide a methodof transforming useless heterogeneous mixtures of such substances intostable, homogeneous adjuncts of substantial value and effectiveness.Other objects and advantages of the present invention will becomeapparent from the following description.

It has been discovered previously by our co- Workers that a compositioncomprising the waterinsoluble metal soaps of preferentially water-soluble sulfonic acids derived from acid sludge, an aromatic hydrocarbon,alcohol, a small amount iii) iii)

of water and some mineral oil is; particularly suitable as an adjunctfor bituminous paving materials. Such a novel composition and a methodof preparing same are described in copending application for LettersPatent Serial No. 108,428, filed August 3, 1949.

Briefly stated, a novel process is described in the copending,application wherein, a hydrolyzed sludge resulting from acid treatment.of a technical white oil or the like with concentrated or fumingsulfuric acid is diluted with more than about 3 volumes of water foreach volume of hydrolyzed acid sludge and mixed with sufficient basiccompound to neutralize the sulfonic acids present therein; theprecipitated sulfonatesare then removed from supernatant liquid andmixed with 25 percent to about '75 percent of an arcmatic hydrocarbonhaving a boiling point of at least about 220 F. following which thearomatic hydrocarbonesulfonate mixture is dehydrated to a water contentof not more than about. 35. perment and there is added to the dehydratedmixture from about 2 percent to 15 percent of an aliphatic alcohol. Thatprocess usually results in stable homogeneous sulfonate compositions butit has been found that for some unknown reason such compositions are attimes unstable and settle in a non-homogeneous two phase mixture. Inorder to assure consistent production of a stable, uniform composition,containing waterinsoluble soaps 0f preferentially water-soluble acidsderived from any sludge obtained in the manner hereinafter described ithas been found desirable to incorporate preferentially oil-solublesulfcnic acids or their soaps, such as mahogany acids or their soaps,to, the composition at some stage in the manufacturing process. Theimprovement of this invention may be employed in the production ofvstable sulfonate compositions from the acids obtained from any sludgeobtained in the manner hereinafter described, as a stability assurancefactor, or it may be employed, if preferred, only When it is apparentthat such is required because of ultimate production of an unstableheterogeneous product.

In accordance with the present invention a stable homogeneouscomposition containing a water-insoluble metal salt of sulfonic acidsderived from acid sludge resulting from the treatment of hydrocarbonoils such as lubricating oil distillates, with sulfuric acid of at least95 percent strength, may be obtained by forming such metal sulfonates insitu in the hydrolyzed acid sludge in the manner hereinafter described.To

a sludge of the type described above is added an amount of mahogany acidof from about 0.5 to about 35 weight percent, preferably from about 5 topercent. Following this the acid sludge is hydrolyzed and settled topermit stratification with sulfuric acid resulting from the hydrolysis.The stratification and subsequent removal of the sulfuric acid (bothunreacted and that resulting from th decomposition Of sulfuric acidesters) from the liver is commonly referred to as hydrolysis of thesulfuric acid sludge and such portion shall be hereinafter solelyreferred to. While it has been found advantageous to incorporateoil-soluble mahogany acids in the sludge prior to hydrolysis of thesludge, the acid or the soap thereof may be incorporated at other stagesin the process since the stage at which such is incorporated is notcritical in this invention. After withdrawing the sulfuric acid theremaining portion of the acid sludge, commonly referred to as liver, isdiluted with water. It is important that the liver be sufficientlydiluted with water at this point prior to the neutralization step, sincein a properly diluted liver the metal sulfcnate formed uponneutralization is preferentially precipitated rather than the metalsulfate thus resulting in a metal sulfonate of low inorganic saltcontent. The dilution required to obtain the preferential precipitationof the metal sulfonate is dependent upon the concentration of sulfonicacid and sulfuric acid in the liver. In general, the liver, or separatedhydrolyzed sludge, should be diluted with more than about 3 volumes ofwater, and preferably at least 5 volumes of water for each volume ofliver. The diluted liver is then heated to a temperature of from about90 F. to about 200 F. and preferably from about 120 F. to about 150 F.and the sulfonic acid i neutralized with a suitable neutralizing agent.The oil-soluble mahogany acids may be added to the diluted liver priorto neutralization in an amount equal to that set forth above foraddition to the sludge prior to hydrolysis but care must be taken tomaintain the required dilution. The metal soaps of the mahogany acidsmay be added to the sludge if they are more readily available, as is thecase in many refineries, otherwise the acid is added and neutralizedalong with the sludge acids. If addition of the sulfonic compound ismade after neutralization, it is preferred that the soaps, rather thanthe acids, be added. Suitable neutralizing agents for use herein are,for example, an oxide, hydroxide or carbonate of the desired metal, forexample, an alkaline earth metal such as calcium, strontium, barium or aheavy polyvalent metal such a lead, iron, zinc. copper, cobalt,manganese, etc. although the alkaline earth metals, particularlycalcitun, are preferred. Other suitable neutralizing agents are basicnitrogenous compounds, such as, for example, ammonia toluidine, etc. Theneutralizing agent is preferably added in the form of a slurry and thereacting mixture agitated such as by air blowing to accelerate thereaction and prevent excessive settling of the neutralizing agent. Afterthe desired amount of the neutralizing agent has been added, theprecipitated metal sulfonate is allowed to settle and the supernatantliquid drawn off, the aromatic hydrocarbon of the type hereinafterdisclosed is added to the crude sulfcnate mixture in amounts of fromabout percent to about '75 percent by weight, and preferably from aboutpercent to about and the aromatic hydrocarbon are well mixed,

sufiicient neutralizing agent is added to completely neutralize theresidual acidity of the material. The neutralized mixture of sulfcnateand aromatic hydrocarbon is dehydrated to lower the water content tofrom about 1 percent to about 35 percent, and preferably from about 3percent to about 10 percent. Whereas the neutralization of the sludgeacids can not be carried out, according to the present invention, withsodium hydroxide or other base which yields a preferentiallywater-soluble soap, the sodium soap of the preferentially oil-solublesulfonic acid may be employed advantageously.

The extent to which the neutralized product is dehydrated will depend tosome extent, upon the type of alcohol used. For example, when usingalcohols of up to about five carbon atoms dehydration to a water contentof from about 1 percent to about 10 percent is desirable, whereas whenusing higher alcohols, such as, for example, nonyl alcohol, cetylalcohol, etc., dehydration to a water content of about 35 percent willbe sufficient to prevent phase separation. The dehydrated mixture icooled to a temperature of at least about F. and the mixture dilutedwith from about 2 percent to about 15 percent, and preferably from about4 percent to about 8 percent. of the aliphatic alcohol. After settlingto remove excess amounts of inorganic salts, which may still be present,the mixture is ready for storage, or for compounding with the bitumenmaterial. In the event it is preferred to add the oil-soluble soaps onlywhen absolutely needed it is at this point that the need will beapparent if a heterogeneous mixture exists. When such is the case,oil-soluble soap addition, made at this point in the process, willresult after agitation of the mixture, in a homogeneous composition.

It is important that th finished mixture contain not more than themaximum amount of water indicated above since'the presence of largeramounts of water will increase the danger of a phase separation ofWater, alcohol, and soap mix ture from the aromatic hydrocarbon.However, when the amount of water present is maintained within theabove-mentioned limits a stable homogeneous product may be obtained withthe addition of a minimum amount of oil-soluble soap.

The sulfcnate composition obtained in the manner described containsessentially the following components in the following approximateproportions:

Preferred Range (Percent) 3 5 Metal sulfcnate oi preferentially watcr-10 to 50 20 to 30.

soluble sludge acid. Aromatic hydrocarbon 25 to 75 35 to 60. AliphaticalcohoL. 2 to 15. 4 to 8. Water l to 35.--" 3 to 10. Hydrocarbon oil 1to 30. 5 to 10. Metal sulfcnate of added oil-soluble sul- .05 to 18... lto 6.

ionic acids.

ated naphthalenes.

carbons suitable for use in the present; invention is a light catalyticcycle stock obtained from a catalytic hydrocarbon cracking operation inwhich gas oil or heavier hydrocarbons, such as reduced crude, arecracked at a temperature of about 800 F. to 1050 F. at a pressure ofabout atmospheric to 50 pounds per square inch in the presence ofsuitable catalysts, such as for example, silica-alumina,silica-magnesia, and other well-known cracking catalysts. A method ofconducting a fluidized catalytic cracking operation is described in U.S. 2,341,193, issued to Fred W. Scheineman, February 8, 1944. Thefraction .suitable for use in the present invention is aheavier-than-gasoline fraction usually recycled to cracking. Thesefractions, depending upon their boiling range, are commonly referred toas light cycle stock and heavy cycle stock. A catalytic light cyclestock particularly well suited for this invention is a fraction havingan arcmatic content of at least about 40 to about 50 percent, and adistillation range between about 425 F. and about 560 F. A typicalanalysis of a suitable light catalytic cycle stock shows the material tobe composed substantially of about percent normal C12 to C parafiins,about 45 percent of other parafiins and naphthenes, about 5 percentmono-nuclear aromatics which are mainly monot hexa-alkylated benzenes,and about 40 percent poly-nuclear aromatics which are mainly alkylnaphthalenes, largely methyl- A typical light catalytic cycle stock willgive the following A. S. T. M. distillation:

Initial boiling point F 430 10% over F 448 50% over F 4'78 90% over F518 Maximum boiling point; F 552 While we prefer to use a light cyclestock from a catalytic cracking operation of the type abovedescribed,hydrocarbon fractions from othercatalytic hydrocarbon conversionprocesses or thermal hydrocarbon conversion processes are suitableprovided they have a sufliciently high aromatic content, at least 40 to50 percent, and have suitable distillation characteristics, i. e.boilingabove about 220 F.

In place of using the whole catalytic cycle stock we may extract thearomatic components from the cycle stock and use the aromatic extract.The aromatics may be extracted by extraction with the usual and knownsolvents, such as for example, liquid hydrogen fluoride, nitromethane,

liquid sulfur dioxide, etc.

Other mixed aromatic hydrocarbons suitable for use in the presentinvention are mixtures of aromatic hydrocarbons produced by thecatalytic conversion-of aliphatic hydrocarbons by the socalledhydroforming process. This mixture is known in the petroleumrefining artas catalytic reform naphtha bottoms, hydroformer polymers, orhydroformer bottoms. They will be referred to hereinafter as hydroformerpolymers. A process by which the hydroforrnez' polymers are obtained isdescribed in U. S. Patent No. 2,320,147. Briefly, the process comprisestreating virgin or cracked naphtha or mixtures thereof with a solidporous hydroforming catalyst such as an oxide of a metal of group II toIV of the periodic system, such as the oxide of chromium or molybdenum,suitably supported on alumina or magnesia. The conversion is suitablycarried out etc. temperature of 850 F. to

alcohol.

1050" F. and, if desired, in the presence of hydrogen. The hydroformerproducts are fractionated by taking overhead a catalytically reformedgasoline of suitable end point and recovering the higher .boilingmaterials as bottoms, which boil from about 400 F. to about 750 F., andhave gravities of from about 10 API to about 18 API. A typical vacuumdistillation of a hydroformer sample having a gravity of about 12 APIshows the following composition:

Fraction Components Toluene.

Xylenes.

l, 3, 5-Trlmethylbenzenes. l, 3, 4-Irimethylbenzene. l, 2,3-Trimethylbenzene. Tetramethylbenzene. Naphthalenes.Monomethylnaphthalenes. Diuhonyl. Dimethylnuphthalenes.

. Methyldiphenyls.

Trimethylnaphthelenes. Fluorene. Methylfiuorenes. Anthracene andPhenanthrene.

Pyrenc. Tetracyclics and Higher.

A representative hydroformer bottoms fraction exhibits the followingphysical properties:

API gravity 11-22 Refractive index n 1.5911 Specific dispersion 264 ASTMdistillation:

Initial F 448 10% F .465 20% F 472 30% F 4'77 40% F 484 50% ,F 490 60% F501 70% F 516 F .545 F 620 Max. (92% off) F 750 Either the entirehydroformer polymer or lower boiling fractions thereof, such as the 0 to90 percent fraction boiling between about 400 F. and 600 F. or the 0 to50 percent fraction boiling between about 400 F. and 500 F. may be used.

The alcohol employed in the present invention is an aliphatic alcohol,such as for example, ethyl alcohol, propyl alcohol, isopropyl alcohol,butyl alcohol, and amyl alcohols, such as tertiary amyl Higher alcoholsof 9 to 16 carbon atoms and higher are not precluded; nonyl alcohol hasbeen found to be operable.

"While the preferentially water-soluble sulfonic acids employed in thisinvention maybe obtained from acid sludges resulting from the treatmentof viscous hydrocarbon oils having S'aybolt Universal viscosity of from80 seconds to 900 seconds at F. with 0.5 to 9 pounds of concentrated orfuming sulfuric acid per gallon of oil being treated, it is preferred toemploy the acid sludges obtained in the treatment of hydrocarbon oilshaving a Saybolt Universal viscosity at 100 F. of from about 100 secondsto about seconds 'with 2 to 4 pounds of fuming sulfuric acid perfollowing the removal of the acid sludge resulting from the treatment ofan oil with sulfuric acid Methylanthracenes and Methylphenanthrenes.

of 95 percent concentration or above. These sulfonic compounds can beremoved from the oil by neutralizing the acid treated oil with analkaline agent such as ammonia or an alkali, preferably sodium hydroxideto form the corresponding sulfonic acid soaps which are then extractedfrom the oil with 50 percent to 80 percent aqueous alcohol solutions orother suitable means. Because of their characteristic mahogany colorthese sulfonates are known in the petroleum art as mahogany soaps. Theyusually contain about 35 to 50 percent of the actual soap mixed withoil, water and a small amount of salts, such as sodium sulfate, whichare difiicult to remove. While most of the preferentially oil-solublesulfonates are obtained from the acid-treated oil by neutralization withalkali, some of these soaps can be recovered from the acid sludge bysuitable solvents.

The preferentially oil-soluble sulfonic acids have equivalent weights inthe range of from about 350 to about 600 and they vary, according totheir equivalent weight, from highly oil-soluble products in the heaviermaterials to products which in the lower equivalent weight range tendtoward preferential water-solubility. Since the sulfonic acids and theirsoaps vary over wide ranges of equivalent weights and corresponding oiland water-solubilities it should be understood that there is no clearlydefinitive line of demarcation between preferentially oil-soluble andpreferentially water-soluble materials; because of this, it is possibleonly to broadly define proper equivalent weight ranges and to urge therequirement of preferential oil-solubility. This is particularly true inview of the fact that some prefentially water-soluble sulfonic acidshave equivalent weights falling within the range set forth above forpreferentially oil-soluble acids.

The present invention will be more fully described and understood byreference to the following specific examples which are illustrative andin no way intended to limit the scope of the invention.

Example I 17,000 gallons of liver (obtained by hydrolyzing the totalsludge and separating the weak acid) were diluted with water to a volumeof about 85,600 gallons. A lime slurry of 15,500 pounds of lime in62,500 pounds of water was then pumped in and the mixture was agitated.The amount of lime slurry used was slightly in excess of that requiredfor the complete neutralization of the total sulfonic acids present butinsufficient to completely neutralize the total acidity. The mixture wasallowed to settle, after addition of the lime was complete and twolayers formed. The upper layer of slightly acid water was removed andthere was added 15,000 gallons of catalytic cycle stock to the lowerlayer comprising calcium sulfonate. An additional slurry 'of 600 poundsof lime in 6060 pounds of water was then added to render the mixtureslightly alkaline. Having added the cycle stock, dehydration of themixture was begun. During the entire hydration step a two phase systemexisted whereby about 50 percent of the total light catalytic cyclestock added remained as a separate top phase. When about 6.5 percentwater content was reached the bottom phase became so viscous that itcould not be pumped, agitated or sampled. Efforts to bring the total mixinto a homogeneous composition by adding a large amount or isopropanolfailed. At this point approximately 8000 gallons of separated mixpresent in one dehydrating vessel were steamed for 16 hours with opensteam to increase the water content and render the bottom phase morepumpable. A rough analysis of the mix after the steaming showed thefollowing:

Per cent Calcium sulfonate (sludge acid sulfonate) 27 Light catalyticcycle stock 50 Water 8 Salts, free lime, oil 15 To this mixture werethen added 800 gallons of sodium mahogany soap having an analysis asfollows:

Per cent Soap 47.7 Oil 45.5 Water 2.9

After agitation of the mixture a stable one phase system existed.Dehydration to about 3.6 percent water was then effected and about 12percent isopropanol was added.

Example II 2.9 pounds of mixed three pound and three and one-half poundsludges resulting from fuming acid treatment of a technical white oilwere mixed with about 0.3 pound of sodium mahogany soap. This mixturewas then hydrolyzed and the resulting liver separated from the weakacid. The liver was diluted with five volumes of water and sufficientlime-water slurry was added to totally neutralize the mixture and yielda two phase system. After discarding the top water phase approximately0.7 part of catalytic cycle stock based on the amount of precipitatewere added to the water-insoluble calcium sulfonate. The mixture wasthen agitated and dehydrated by air stripping at 185 to 190 F. down to awater content of about 3.5 percent, a one phase system being maintainedthroughout the dehydration procedure. Approximately 10 percent by volumeof isopropyl alcohol was then added to the mixture to give the additive.A second portion of the same sludge was treated in the identical manneras set forth above except that no mahogany soap was added at any point.Upon addition of the catalytic cycle stock to the water-insolublecalcium sulfonate a two phase system existed which, as dehydrationprogressed resulted in a system which was was practically impossible tohandle because of the high viscosity of the lower sulfonate layer.

Example III 15.4 pounds of a plant liver resulting from the hydrolysisof equal volumes of three pound and three and one-half pound sludges,produced in the fuming acid treatment of a technical white oil, weremixed with 2 /2 pounds of sodium mahogany soap. This mixture was heatedto about 210 F. and steamed about one-half hour with pounds open steamto remove the S02. About 85 pounds of water were then added to thesteamed mixture and the mixture was heated to about 180 F. with thoroughmixing. The diluted liver was then neutralized with lime slurryconsisting of 1.9 pounds of lime and about five pounds of water. Airagitation was applied throughout the entire addition of lime and for anadditional hour thereafter to insure proper neutralization. Aftersettling for about 10 minutes a two phase system existed from which thesupernatant water phase was decanted. 23.7 pounds of water-lib solublecalcium sulfonate resulted to which 17.8 pounds of catalytic cycledstock were added while .9 thoroughly agitating same with air. Themixture was then dehydrated to 1.2 percent water by air stripping at 175to 195 F. 0.4 pound of isopropyl alcohol were then added to 25 pounds ofthe dehydrated mixture and thoroughly blended therewith to yield anadditive. An analysis of the material follows:

Per cent Calcium sludge acid sulfonate 20.1 Calcium mahogany sulfonate2.9 Catalytic cycle stock 55.0 Water 1.2 Isopropyl alcohol 1.6 Salts10.0 Mineral oil 9.2

A second portion of the same liver was processed in the same manner asabove without the addition of mahogany soap at any point in the process;a two phase system existed during dehydration which rendered the mixturepractically impossible to handle.

Example IV A finished additive prepared in the manner described hereinhaving a composition as follows:

Per cent Calcium sludge acid sulfonate 27.0 Catalytic cycle stock 47.9Water 7.3 isopropyl 6.2 Salts 0.2 Mineral oil 11.4

was. found to have a tendency to separate into two phases. Upon additionto the above additive, i

vent or reduce the tendency of such materials to stripping from mineralaggregates by water. The amount of the sulfonate composition to be useddepends upon several factors, among which are the type of oil orbituminous materials employed, the area of the aggregate-bitumeninterface, the charactertistios of the aggregate material, the severityof the conditions of use, etc. It will be appreciated that these factorsare interdependent to some extent, and that therefore the quantity ofsulfonate composition which can be used most advantageously will bedetermined for the individual combination of bitumen and aggregate. Ingeneral the amount of sulfonate composition used to produce the besteffects should be sufficient to produce a bitumen composition havingfrom about 0.05% to about 10%, and preferably from about 0.5% to aboutof the 100 percent metal sulfonate, based upon the bitumen used.

Whereas the present invention has been described with particularreference to the use of preferentially water-insoluble sulfonic soapsderived from an acid sludge by the method taught in copendingapplication for Letters Patent Serial No. 108,428, such soaps ofpreferentially water-soluble acids obtained from sludges by other knowntechniques may, likewise, be employed in accordance with the presentinvention.

Percentages given herein and in the appended 10 claims are weightpercentages unless otherwise stated.

We claim: 1. The method of preparing a stable homogeneous polyvalentmetal sulfonate containing adjunct for bituminous materials which com.-

prises recovering preferentially water-soluble sulfonic acids fromsulfuric acid sludge, transforming said acids into preferentially waterinsoluble soaps by adding thereto a sufficient amount of an alkalineearth basic compound to neutralize. said. sulfonic acids, adding. fromabout percent to about 75 percent of a liquid aromatic hydrocarbonhaving a boiling point of at least about 220 adjusting the water contentto not more; than percent, adding about 2 percent to about 15 percent ofan alkanol containing from 2 to about 16 carbon atoms. and adding fromabout 0.05 percent to about 18 percent of. a preferentially oil-solublesulfonic compound. selected from the group consisting of mahogany acidand. metal soaps of mahogany acids.

2. The method of claim 1 in which the arcmatic hydrocarbon is anaromatic fraction boiling from about 400 F. to about 750 F., produced bythe catalytic conversion of aliphatic hydrocarbons.

3. The method. of claim 1 which the alkanol is isopropyl alcohol.

4. The method of claim 1 in which the preferentially oil-solublecompound has an equivalent weight of from about 350 to about 600.

5. The method of preparing a stable homogeneous polyvalent metalsulfonate containing adjunct for bituminous materials which comprisesrecovering the preferentially water-soluble sulfonic acids from sulfuricacid sludge, adding a sufficient amount of an alkaline earth basiccompound to neutralize said sulfonic acids, transforming said acids intopreferentially water insoluble soaps by adding thereto from about 25percent to about '75 percent of a catalytic cycle stock having anaromatic content of at least about 40 percent and having a distillationrange between about 425 F. and about 460 F., adjusting the water contentto fromabout 3 percent to about 10 percent, adding from about 2 percentto about 15 percent of an alkanol of from 2 carbon atoms to about 9carbon atoms, and adding from about .05 percent to about 18 percent of apreferentially oil-soluble sulfonic compound seleoted from the groupconsisting of mahogany acids and metal soaps of mahogany acids.

6. The method of claim 5 in which the alkanol is isopropyl alcohol.

7. The method of claim 5 in which the preferentially oil-solublesulfonic compound has an equivalent weight of from about 350 to about600.

8. In the method of preparing a stable homogeneous polyvalent metalsulfonate-containing adjunct composition for bituminous materials whichcomprises diluting a sulfuric acid sludge which has been substantiallyfreed of unreacted sulfuric acid with more than about 3 volumes of waterto each volume of sludge, adding a sufficient amount of an alkalineearth basic compound to neutralize the sulfonic acids in said acidsludge, removing the supernatant liquid from the precipitated metalsulfonates, adding from about 25 percent to about percent of a liquidaromatic hydrocarbon having a boiling point of at least about 220 F.,dehydrating the mixture of metal sulfonates and aromatic hydrocarbon toa water content of not more than about 35 percent and adding to thedehydrated mixture from about 2 percent to about 15 percent of analkanol containing from 2 to about 16 carbon atoms, the improvementwhich comprises the addition to said composition of from about .05 toabout 18 percent of a preferentially oil-soluble sulfonic compoundselected from the group consisting of mahogany acids and metal soaps ofmahogany acids.

9. The method of claim 8 in which the preferentially oil-solublesulfonic compound has an equivalent weight of from about 350 to about600.

10. The method which comprises diluting sulfuric acid sludge which hasbeen substantially freed of unreacted sulfuric acid, with more thanabout 3 volumes of water to each volume of sludge, adding a sufficientamount of an alkaline earth basic compound to neutralize the sulfonicacids in said hydrolyzed sludge, removing the supernatant aqueous liquidfrom the precipitated metal sulfonates, adding from about 25 percent toabout 75 percent of a liquid aromatic hydrocarbon having a boiling pointof at least about 220 F., dehydrating the mixture of metal sulfonatesand aromatic hydrocarbon to a water content of not more than about 35percent, adding to the dehydrated mixture from about 2 percent to about15 percent of an alkanol containing from 2 to about 16 carbon atoms,adding from about 0.05 to about 18 of a preferentially 'oil-solublesulfonic compound selected from the group consisting of mahogany acidsand metal soaps of mahogany acids and incorporating the dehydratedmixture with a bitumen in an amount of from about 0.05 to about 10percent by weight.

11. The composition comprising a bitumen and from about 0.5 percent toabout 5 per-cent of a mixture consisting essentially of from aboutpercent to about 50 percent of a preferentially water-insolublepolyvalent metal sulfonate, prepared from preferentially water-solublesulfuric acid sludge-sulfonic acids, from about 25 percent to about '75percent of a liquid aromatic hydrocarbon having a boiling point aboveabout 220 F., about 2 to about percent of an alkanol containing from 2to about 16 carbon atoms, not

more than 35 percent water, from about 0.05 to about 18 of apreferentially oil-soluble sulfonic 4 Number compound selected from thegroup consisting of mahogany acids and metal soaps of mahogany acids andup to about 30 percent hydrocarbon oil.

12. The composition comprising a bituminous hydrocarbon and from about0.5 percent to about 5 percent of a mixture consisting essentially offrom about percent to about percent of a preferentially water-insolublecalcium sulfonate prepared from preferentially water soluble sludgesulfonic acids, from about percent to about 60 percent of a solventhaving a boiling point above about 200 F. and an aromatic content of atleast about percent, from about 4 percent to about 8 percent of analkanol containing from 2 to about 9 carbon atoms, not more than 35percent water, from 0.05 to about 18 percent of a preferentiallyoil-soluble sulfonic compound selected from the group consisting ofmahogany acids and metal soaps of mahogany acids and from about 5percent to about 10 percent hydrocarbon oil.

13. The composition of claim 12 in which the solvent is a catalyticcycle stock having an arcmatic content of at least about 40 percent anda distillation range between about 425 F. and about 560 F.

14. The composition of claim 12 in which the solvent is a bottomsfraction of a catalytically reformed gasoline, said bottoms having adistillation range of from about 400 F. to about 750 F.

15. The composition of claim 12 in which the alkanol is isopropylalcohol.

16. The composition of claim 12 in which the bitumen is a normallyliquid petroleum oil residuum.

17. The composition of claim 12 in which the metal soap of the mahoganyacid is sodium mahogany sulfonate.

18. The composition of claim 12 in which the metal soap of the mahoganyacid is calcium mahogany sulfonate.

References Cited in the file of this patent UNITED STATES PATENTS NameDate Merrill Dec. 11, 1928 Stamberg Nov. 11, 1930 Ramayya Nov. 21, 1933Roediger Oct. 19, 1943

1. THE METHOD OF PREPARING A STABLE HOMOGENEOUS POLYVALENT METALSULFONATE CONTAINING ADJUNCT FOR BITUMINOUS MATERIALS WHICH COMPRISESRECOVERING PREFERENTIALLY WATER-SOLUBLE SULFONIC ACIDS FROM SULFURICACID SLUDGE, TRANSFORMING SAID ACIDS INTO PREFERENTIALLY WATER INSOLUBLESOAPS BY ADDING THERETO A SUFFICIENT AMOUNT OF AN ALKALINE EARTH BASICCOMPOUND TO NEUTRALIZE SAID SULFONIC ACIDS, ADDING FROM ABOUT 25 PERCENTTO ABOUT 75 PERCENT OF A LIQUID AROMATIC HYDROCARBON HAVING A BOILINGPOINT OF AT LEAST ABOUT 220* F., ADJUSTING THE WATER CONTENT TO NOT MORETHAN 35 PERCENT, ADDING ABOUT 2 PERCENT TO ABOUT 15 PERCENT OF ANALKANOL CONTAINING FROM 2 TO ABOUT 16 CARBON ATOMS AND ADDING FROM ABOUT0.05 PERCENT TO ABOUT 18 PERCENT OF A PREFERENTIALLY OIL-SOLUBLESULFONIC COMPOUND SELECTED FROM THE GROUP CONSISTING OF MAHOGANY ACIDAND METAL SOAPS OF MAHOGANY ACIDS.